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[RAM]

Astrophysics comes up because some people go looking at the edges of the universe looking for something to be incomplete, to prove that an outside force sustains the world. Others look for consistency to prove that no such force is required. I would like to suggest that there is far too much detail for an intelligent creator. people would have accepted atoms as, well, atoms, sub-atomic particles really aren't necessary and I am not familiar with many minds that would would go into so much needless detail, unless humanity really isn't a significant part of the project...

Because the Universe is where atheists look for god to check if he really doesn't exist.

"atheists" "really doesn't exist"...

light slows and eventually stops at massive gravitational points.

True? Not true(as far as our current understanding goes, etc.). You must've been thinking about time.

Light is subject to gravity. If time stops then, well, light may maintain its velocity but... If light changes direction, gets dispersed, and travels through an environment whose composition people are still arguing about, then it is somewhat difficult to get a convincingly definitive description from it after it has been travelling for untold ages...

[Neruz]

yeah, that sounds more correct with time.  but light cant esacpe black holes so, i am assuming, it isnt moving at a constant rate anymore.  will the PHD's please correct me?

It's because of the innate perculiarity of photons; they have no mass but they do have energy (which in initial conventional physics should have been impossible, we now know better). Due to the way that Gravity functions on a spatial scale in sufficient quantities it can have an effect on that energy, 'pulling' it around. This, combined with the massive time flow distortions and eventual ceasing of said flow at the event horizon causes light to bend around black holes much in the same way that it can be refracted through a prism, and due to the time flow stoppage and the fact that the light gets stretched out as it is subject to intense gravitational forces (which manifests in a red-shift) is what causes the event horizon.

Or, to put it simply; when we state that c is a constant in a vacuum, it's meant literally; as in nothing at all in that space except for the light, including gravity.


But then again, gravity is a funny force.

[Ampersand]

Not quite. Light will still appear to be moving at C to an observer within the black hole. A more accurate way to state it is that the Relative speed of light to any given observer in any position in space, in a vacuum, is always C. It doesn't matter if you are traveling at 99 percent of C, from your point of view, a beam of light moving in parallel to you will still travel at C relative to you, due to Time Dilation. Similarly, in a distorted space, such as that around a Black Hole, light will still travel at C relative to an observer within that distorted space, even though it may appear otherwise to an outside observer.

[Sergius]

i do not think the speed of light is a constant, in the context I think your using it.  light slows and eventually stops at massive gravitational points.  We have no idea what kind of gravitational boundaries might exist between systems, galaxies, etc.

Even if (hypotetically) LIGHT slowed down. The SPEED OF LIGHT doesn't slow down, as it is a constant. Just because a beam of light passed next to some massive gravitational point, does that mean that suddenly, all light everywhere across the universe has slowed down? No.

[Gorjo MacGrymm]

*sagely nods, as if to imply he understands this stuff, which he doesnt

[RAM]

I suspect that once you have people claiming a localised stopping of time you can have a localised modification of just about anything. 'If' a massive gravity well altered the speed of light within its influence I don't see why that would affect the speed of light everywhere...

[Ampersand]

A black hole does not stop time, nor does it stop light. It merely severely bends both space and time, such that, if we were to plot the points in a black hole on a graph, there is no straight line from any point within the event horizon that leads to any point outside of the event horizon.

[G-Flex]

On the other hand, a black whole doesn't act like the sort of matter-vacuum portrayed in sci-fi, or at least not in all the ways portrayed.

If the Sun turned into a black hole right now (which it couldn't due to mass, but  let's assume here the Sun is larger or whatever), we'd still be orbiting it the same since it would be exerting the same gravitational attraction on us. Same mass, same distance. The important thing about black holes is just that they exist as a pinpoint of mass, so you can get really damn close and THEN get sucked in.

[Neruz]

A black hole does not stop time, nor does it stop light. It merely severely bends both space and time, such that, if we were to plot the points in a black hole on a graph, there is no straight line from any point within the event horizon that leads to any point outside of the event horizon.

Yes and no; time, space and light are all relative. From outside the Event Horizon they appear to be stopped inside it, presumably the reverse would be true.

[Starver]

I am rather confused how they are defining the "edge" of the universe, since it's likely we can't even see it.

The "edge of the universe", as opposed to the "edge of the <whatever> universe"?

Well, that's a different thing from the visible/known edge (although it's something that we're trying to get the "known-ness" about up to, at least at an initial low resolution of knowledge).

That would be the entirity of the universe's volume to the extent that it reaches.  Right now that's advancing into the 'whatever' (if you're assuming it's actually a wavefront advancing into the 'nothingness' that contains the 'somethingness' of the universe), or is just the outmost reaches of the bubble that is 'everything-it-can-be', or might actually be an arbitray point (the antipodal point to 'here', writ large and multi-dimensioned) if it's actually a case of finding a distance beyond which you have gone so far away that you're heading back towards us, like the 180°E/W line is on a standard map.

If you're into taking time as a valid dimension of movement, then the point of the Big Bang and additionally (if it comes back to a singularity) the one of the Big Crunch could be considered the 'edge', much as the North (and South) Pole can be considered an 'edge' to the map of the world.

Depending on your view of the situation (and in "multi-iniverses in a metauniversal space" theories, there are other viewpoints), the actual edge of the Universe is generally held to be equivalent to how the Heliopause is to solar wind (but not, of course, its light, and the "edge of the universe"'s edge is assumed to be the extent of the actual light/radiation from everything that has ever lit up its insides, and most probably the light that came from the initial event, though of course "Inflation" has been described as a FTL 'blowing up of the balloon of the universe', which to some people means that there was just more space inbetween things, to others that there was more space to expand into...  tricky thing to decide on, really.

From another POV, the event horizons of black holes could be considered the edges, given that only stuff this side of them actually counts (Hawking Radiation, aside, and however this and the residual charge/etc of the evaporating black hole makes the 'contents' felt in the 'real universe').  Treating the 'edge' as if it were our event horizon (from the inside) is another possibility, especially given the theories of black holes essentially twisting space and time around, reversing their natures (a simple mathematical trick), so why couldn't we be inhabitants of a black-hole in a 4D (three time, one space) universe.  (Except insofar as gravity is not supposed to work in universes with less than three dimensions to propogate, but on the other hand tachyons theoretically do exist, so maybe they perform the function of the 'graviton'... that's another discussion and a half, what with things switched around from how we're familiar with.)


Am I making sense?  Probably not, until I can pursuade IE not to keep scrolling back the textarea box so I can see what I'm writing.

[Starver]

Astrophysics comes up because some people go looking at the edges of the universe looking for something to be incomplete, to prove that an outside force sustains the world. Others look for consistency to prove that no such force is required. I would like to suggest that there is far too much detail for an intelligent creator. people would have accepted atoms as, well, atoms, sub-atomic particles really aren't necessary and I am not familiar with many minds that would would go into so much needless detail, unless humanity really isn't a significant part of the project...

There's an interesting parallel to something I heard recently about Newton and Liebnitz (co-developers of integration/differentiation, and not a little friction between them regarding who, if either, copied off of who).

To paraphrase (to the best of my recall, and thus also the opinion of the person I am recalling), Newton considered gravity to be God constantly using his omnipotent powers to keep the planets orbitting the sun, and the apple falling towards the Earth and people standing upon it were held down by the ever-constant attention of God.  Liebnitz was more of the opinion that God was still as responsible, but had set it up to do so, and although He could interfere to negate the process (equivalent to allowing His attention to waver, in terms of Newton's) was cleverer (and/or lazier) than Newton would have Him be.

My personal concept of any God is of a "Fire and forget" being.  Poke the Big Bang into existence and sit back and relax.  Any all-powerful deity worth his Pillars Of Salt is going to be able to spark the universe up exactly the way He needed to in order to develop the life he wants.  Either in His image or just generally.  If, indeed, life was the aim and not just a side-effect (reference back to that Theologian tale that I think was mentioned a few dozen pages back in this very thread) or whatever other Grand Purpose (or experiment, or just messing around) was the reasoning behind Creation.

Another personal concept is of God's Kitchen, with a table (possibly infinite in size) containing a number of jam jars (possibly an infinite number), each of them having a slightly different mix of "Universe" within them.  Some sit there doing very little, some bubble a bit, one or two my sputter and spurt and start to leak over the edges.  All very interesting.  Of course, is our jam jar doing anything unusual?  Or is it not doing enough?  For all we know, God wanders round the table and hoiks off the occasional jar that's about to spill over and contaminate the neighbouring ones, and chucks it down the sink, or considers the fate of the jars where it's a seemingly inactive brown sludge at the bottom and nothing else, to similar fate.  And who knows if we'll be left to 'do our stuff'.


But the above are merely thought experiments.  Given that we seem (to all current evidence) to have a Fire And Forget-style God, if we have one, then the deity concerned isn't really bothered enough, and so I deal with the world (i.e. universe as we see it) as if it were just an isolated system without any such deity.  What that means for my future (i.e. afterlife, if there is one) is another issue, of course, but my expectations are rosy, should such an eventuality become important, as long as I follow the logic I might be expected to follow, in the absence of any reason (which, honestly, I could never foresee existing) to pursue more religious expectations.

[Neruz]

If you've got a truely Omnipotent and Omniscient being, then he only needs the one poke; he knows how to get the universe exactly the way he wants it to be from any given starting point thanks to his Omniscience, and he can do it thanks to his Omnipotence.

If the being has to do maintainence, then something went wrong, if something went wrong he either knew it would go wrong but could not stop it, in which case he is not Omnipotent, or he did not know it would go wrong, in which case he is not Omniscient.


As for people being in God's image. Well. Best not go there, it's even more rediculous.

[RAM]

If a being is truly omniscient and omnipotent and actually uses these faculties then actually creating a universe is completely redundant, identical results could be achieved with a thought experiment. Which raises the obvious questions. Are we a thought experiment? How do we view our thought experiments?

[Neruz]

At which point you run into the good old perception and reality quandry.

[Cheeetar]

ridiculous.

Fixed. And away I go!